Photograph by: Jenelle Schneider
, Vancouver Sun

B.C. officials insist the province’s aging bridges are safe following a “freak” accident that brought down a bridge over the Skagit River in Washington State on Thursday night.

In Metro Vancouver, there are several crossings that are more than 50 years old, including the Pattullo, Burrard, Granville Street, Lions Gate and Ironworkers’ Memorial bridges. But officials say they have all been kept in a state of good repair by regular inspections and maintenance.

“It’s like a house or a building. With proper maintenance, they can go on for well over 100 years,” said Jerry Dobrovolny, Vancouver’s transportation director.

The province requires all crossings to be inspected at least once a year, but most municipal bridges are examined more frequently than that.

But officials acknowledge more sophisticated inspection tools could be used.

The province has responsibility for the upkeep of 2,700 bridges in B.C., and is slated to spend $120 million on rehabilitation and repairs in the next three years.

“We want to get the message out — our bridges are safe,” said the province’s chief bridge engineer Kevin Baskin.

While B.C. does not have a bridge safety rating system as exists in the U.S., annual inspection results are fed into a provincial database that sets repair priorities, said Baskin.

Inspectors look for telltale cracks and use hammers to chip away at concrete that may be pulling away from reinforcing steel, using a boom crane to get to difficult spots.

University of B.C. civil engineering professor Nemy Banthia is concerned, however, that these methods don’t provide enough information on the condition of the province’s bridges.

Banthia pointed to the collapse of a Quebec overpass in 2006 that killed five people. He noted the Quebec bridge was inspected the same week it collapsed.

“That raises a whole bunch of issues. Do we, in fact, have the proper condition assessment tools? My answer to that is, no,” said Banthia, a Canada Research Chair in Infrastructure Rehabilitation and Sustainability at UBC.

He noted that UBC is doing research using thermographic resonance imaging on bridges, which detects heat signatures that pinpoint weak points.

Banthia is also an advocate of putting embedded sensors in bridges, which would provide real-time data on loads and stresses.

Such sensors are providing data on a bridge on Vancouver Island, but he would like to see the devices installed in all key crossings.

Neither technology is prohibitively expensive, he said.

Baskin said he agrees that there is a need to use more sophisticated bridge inspection tools, noting the province is working with Banthia.

In Vancouver, the city has spent about $26 million on the Burrard and Granville bridges during the past 20 years for maintenance, seismic upgrading and rehabilitation. A further $17 million has been set aside for the two bridges.

“Absolutely the bridges are safe. They’re in good condition,” said Jerry Dobrovolny, the city’s director of transportation.

TransLink is responsible for the Pattullo, Knight Street and Golden Ears bridges, as well as the 100-year-old Westham Island Bridge in Ladner and the new Canada Line cycling and pedestrian bridge. It spends $1.5 million to $1.8 million annually on operations and maintenance of its bridges, and insists the crossings are safe.

Every year, contractors look under the bridge spans and hard-to-reach locations using a “snooper” truck, which has a large crane or bucket attached to search for any potential cracks or faults in the girders and support systems, spokesman Derek Zabel said.

Inspections are more regular on the Pattullo because of its age. The bridge is slated to be rebuilt or rehabilitated to bring it up to seismic standards, but there is no money in the TransLink budget at this time.

The deadliest bridge disaster in B.C. occurred in 1958, when the then half-built Second Narrows bridge collapsed and 27 workers died.

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